There’s an interesting Malayalam (one of the official languages in India) movie titled “Virus” [1] from 2019, which is set during the time of the 2018 Nipah virus outbreak in Kerala (a state in South India). The disease is deadly and can have longer incubation periods (as stated in other comments here). Wikipedia says the mortality rate is 40-75%.
seems like a common occurence in the region, although the virus is highly contagious and very deadly.
As long as it is very deadly I think there is a reduced risk of global pandemic, the hosts are easily isolated and the risk mitigated. I think the problem is if this virus stays dormant for a prolonged period or if the symptoms pass for something else during the early stages. Covid-19 had both of those, 72 hours of no symptoms and then 2-3 days of what looks like a regular cold or mild flu.
The incubation period is 4-14 days, and in rare cases up to 45 days. So it would seem to pose one of the problems you identified.